The cartouche on the receiver looks art deco - late 1920's, Weimar era.
With that barrel, the round would probably pack about the same heat as a Russian ппщ (pay pay sha) submachine gun which uses a similar 7.62x25 cartridge.
7 posted on 03/09/2015 5:16:18 PM PDT by InABunkerUnderSF
(Flu season: Wash your hands.)